3 IntroductionUsing silica fume as an enhancer for the concrete beams, slabs, columns and any other concrete structure.Concrete is very good material in compression however it is very week in tension so that is way we use reinforcement in it.3Silica Fume influence on RC Beams BehaviorDepartment of Civil and Environmental Engineering

5 Why Silica Fume ? Change microstructure of the concretePhysical aspect of silica fume :Fills in the spaces between cement grainsChemical contribution :Cement releases calcium hydroxide.Silica has very high silicon dioxide.Calcium hydroxide will react with silicon dioxide to form calcium silicate hydrate.5Silica Fume influence on RC Beams BehaviorDepartment of Civil and Environmental Engineering

6 IntroductionConcrete solidifies and hardens after mixing and placement due to a chemical process known as hydration. The water reacts with cement which bonds the other components together eventually creating a stone-like material.Reinforcement is a good indication for failure because it gives us a warning.6Silica Fume influence on RC Beams BehaviorDepartment of Civil and Environmental Engineering

10 Split cylinder testThis test, often referred to as the split-cylinder test, indirectly measures the tensile strength of concrete by compressing a cylinder through a line load applied along its length.10Silica Fume influence on RC Beams BehaviorDepartment of Civil and Environmental Engineering

11 The testing machineThis test can be completed in a standard concrete compression testing machine, with only one special requirement the hinged bearing that loads the specimen.11Silica Fume influence on RC Beams BehaviorDepartment of Civil and Environmental Engineering

18 PermeabilityPermeability describes the ease by which any species (i.e. liquid or gas) can pass through concrete.Objective :Effect of silica fume in permeability of concrete on different percentage (0%,7.5%,10%,12.5%)18Silica Fume influence on RC Beams BehaviorDepartment of Civil and Environmental Engineering

19 Permeability Most popular fluid is water Most popular gas is O2 & CO2ConcreteSpecimenInflowFlow pathOutflowWater permeatingthrough concrete19Silica Fume influence on RC Beams BehaviorDepartment of Civil and Environmental Engineering

31 The silica fume will effect on the permeability as shown in the chart, when the quantity of silica fume increase the permeability will decrease.31Silica Fume influence on RC Beams BehaviorDepartment of Civil and Environmental Engineering

50 What is Flexural Strength ?One measure of the tensile strength.Measure of an unreinforced concrete.Loading beams with tow concentrated load.50Silica Fume influence on RC Beams BehaviorDepartment of Civil and Environmental Engineering

70 Conclusion All the tests results were very encouraging.Adding the silica fume to any concrete mixture will enhance the properties of the concrete far beyond its initial properties.Increasing the amount of silica fume will result in enhancing the concrete properties.70Silica Fume influence on RC Beams BehaviorDepartment of Civil and Environmental Engineering

71 Conclusion The silica fume is a very promising industry in the future.For the next semester it is recommended for one of the GPI groups to investigate the influence of fly ash on concrete and compare it with our results.71Silica Fume influence on RC Beams BehaviorDepartment of Civil and Environmental Engineering